— In this paper we analyze the performance of two different routing protocols specifically designed for Wireless Sensor Networks (WSNs) for real-time estimation, control, and monitoring. These protocols are designed to compensate for the lossy nature of the wireless links and the delay from sending messages over multiple hops from the sensors to the controller. The routing protocols are designed to reduce packet delay and packet loss using either retransmissions or multicasting. For some routing topologies one protocol may be better than the other at reducing the worst case packet delay but may have a worse packet loss rate. Here, we apply mathematical tools to analytically compute the average real-time performance based on end-to-end packet delay statistics for two recently proposed routing strategies. We show that the performance is strongly related to the dynamics of the systems being estimated, and we construct a computationally efficient estimation strategy based on the delay ...